GWD 24-18

24-18 Most household appliances use electricity only when in use. Many microwave ovens, however, have built-in clocks and so use some electricity even when they are not in use. The clocks each consume about 45 kilowatt-hours per year. Therefore, households whose microwave oven has no built-in clock use 45 kilowatt-hours per year less. On average, than do comparable households whose microwave oven is otherwise similar but has a built-in clock.

Which of the following is an assumption on which the argument depends?

A)    Households that do not have a microwave oven use less energy per year, on average, than do households that have a microwave oven.

B)    Microwave ovens with a built-in clock do not generally cost more to buy than microwave ovens without a built-in clock.

C)    All households that have a microwave oven also have either a gas oven or a conventional electric oven.

D)    Households whose microwave oven does not have a built-in clock are no more likely to have a separate electric clock plugged in than households whose microwave oven has one

E)    There are more households that have a microwave oven with a built-in clock than there are households that have a microwave oven without a built-in clock.

此题选D，蒙对的，其他的怎么排除？想不太明白的说。

题干中比较：微波炉有无内置表的用电情框。

A：比较的是有无微波炉的情况，而不是微波炉有无内置表的情况，无关。

B：比较哪种更贵。无关

C：很明显无关

D：没有内置表的微波炉不太可能有外置的表（同样也耗电）。取非，weaken结论。

E：无关

按这么解释别人还是迷糊的,这些都是考试机器人写的话.什么取非不取非的,就没看懂原文的含义.

日常生活常识的解释:

电子钟的用途就是让家电到时候会停止工作(节能).

很自然,要想有电子钟的电烤炉比无电子钟的烤炉仅仅多个电子钟的耗电量.自然是不能给无电子钟的烤炉加装电子钟.(哈哈,不会停的烤炉东西烤糊了了)

同样道理,会自动停的充电器和不会自动停的充电器,大家明白否??

前提:家用电器只在使用的时候用电

然而:有内嵌时钟的微波炉 在不使用的时候也耗电 ，那些时钟每年消耗 45 度电

结论:平均来说，无内嵌时钟的微波炉比有内嵌时钟的微波炉少耗45度电每年

这题应该是排除他因

A,没有用微波炉的家庭，无关

B,购买价格，无关

C,传统电炉，无关

D,排除他因，就是排除微波炉除了正常使用，和时钟耗电无别的耗电，正确

E,更多地家庭使用带有时钟的微波炉，文中提到average use，因此无关

本人漏见，欢迎批判！